Filtration of wastewater involves causing small, suspended particles to cluster together and settle. This process includes two steps, namely “coagulation” and “flocculation.” “Coagulation” refers to driving together of colloidal particles by chemical forces. “Flocculation” refers to assembling the coagulated particles into clumped masses, called “flocs,” which settle out of the wastewater. Flocculation may use a chemical-bridging mechanism, enhanced by the use of substances like polyelectrolytes.
Wastewater filtration systems are widely used in public sanitation and industrial enterprises. However, residential use of such systems is generally limited to applications such as clarifying water in ponds, swimming pools, and the like.